The principle of NiMH battery charger mainly includes the following key parts:
Circuit design: The circuit design of NiMH battery charger usually includes components such as transformer, rectifier circuit, current limiting resistor, rectifier diode, etc. The transformer is used to convert AC power into a voltage suitable for battery charging, the rectifier circuit converts AC power into DC power, and the current limiting resistor is used to limit the charging current to prevent excessive current from damaging the battery.
Charging process: The charging process of NiMH battery can be divided into the following stages:
Constant current charging stage: When the battery voltage is low, the charger charges the battery with a constant current until the battery voltage reaches a certain level.
Constant voltage charging stage: When the battery voltage reaches a certain value, the charger switches to constant voltage charging. At this time, the battery voltage will slowly rise and the current will gradually decrease until the battery is fully charged.
Protection mechanism: In order to prevent overcharging and overheating, the charger usually also includes an overcharge protection circuit and a temperature control device. When the battery voltage reaches the set value, the charger will automatically stop charging to prevent the battery from overcharging. At the same time, the temperature control device monitors the temperature changes during the charging process to ensure the safety of the charging process.
Actual application case: For example, a simple NiMH battery charger may contain a transformer, a rectifier circuit, and a current limiting resistor. The transformer converts the mains power to a voltage suitable for battery charging, the rectifier circuit converts AC power to DC power, and the current limiting resistor limits the charging current. When the battery is full, the charger will automatically stop working.
